How climate change will hit our coasts

The impact of climate change on coastal Australia will be immense, according to a federal parliamentary report released last week. We need to prepare now for the inevitable shocks to come. [3 November 2009 | Peter Boyer]

Australians’ love of the sea-shore will be sorely tested by rising sea levels

Australians’ love of the sea-shore will be sorely tested by rising sea levels

Those old outback symbols of our nation — the swagman, the drover’s wife, the bush humpy — have retreated far into the background. If we’re looking for an icon for modern Australian life, we should forget the wide brown land.

It’s our coasts that carry most meaning for most Australians. As an icon, the beachside retreat would be a pretty fair start. What matters to us is the shore and the breakers beyond. We can’t get enough of them.

Eighty per cent of Australians live close to the sea, with over 700,000 properties within 3 km of the coast and less than 6 metres above sea level — and the proportion is growing as more and more people pursue their sea change to the small coastal town.

Now there’s a new reason to focus on the coast — but it’s nothing to celebrate. A federal parliamentary report on coasts and climate change provides plenty of evidence that our dream waterside mansions or weekend shacks may one day turn into nightmares.

The trouble starts with the restless sea. The House of Representatives Committee on Climate Change has found that rising sea levels, already a growing problem for a few vulnerable property owners, will become a massive national headache in coming decades.

As any coastal real estate guide will tell us, waterside properties cost a lot of money, which benefits local and state authorities in the form of high rates and property taxes. In return, the coastal property owner expects high-quality infrastructure support, like sea walls, access roads and town water.

If one seaside property owner has a problem, you can bet it will be shared with the authorities. If there are lots of them with problems, government everywhere, at all levels, will be feeling the heat. If we don’t do something about our complex, fragmented coastal administrative arrangements over multiple jurisdictions, the nightmare can only get worse.

Our seas are already on the rise, at the rate of around 3 mm a year. The most likely scenario at the end of this century, according to scientific evidence to the committee, is a rise of 80 to 90 cm.

That may seem manageable if your property is more than a metre above sea level, but it’s not the end of the story. The committee took expert advice that warming ocean waters will cause a rising frequency and intensity of storm events, bringing “extreme sea levels”. Combined with high tides and heavy rain, large areas of normally unaffected coastal land will be flooded.

The problem compounds with higher sea levels. As an example, if our seas were to rise by half a metre by 2100, there would be a 300 times greater likelihood of coastal flooding. A flooding event that happens once a year at the moment would by 2100 be happening nearly every day.

Though real estate problems will have the highest profile, there will be many more headaches from rising seas. Besides disruption to road, power and communications links, saltwater flooding of coastal areas will cause contaminated and disrupted water supplies and have consequences for food production, human health and ecological systems.

Nearly all Tasmanian municipalities take in coastlines. If their authorities aren’t moved to action by this, they should be. But the task of dealing with the problems will be well beyond them, as it will be for the states. The ultimate responsibility will rest with Canberra.

The committee’s strong views on this pressing problem stem from its own experience in hearing expert evidence and visiting coastal areas already under threat. We can only hope that its sense of urgency spreads throughout the breadth and depth of all our governments — and quickly.

So, what should you do if you’re on a waterfront block? There are the obvious things, such as finding out how vulnerable you are (height above current sea level, geology of the ground you’ve built on, exposure to sea weather) and what can be done to protect your investment.

Above all you need to remind yourself that having a home by the water, whatever its future uncertainty, is truly a privilege. We need to think about our long-term future, but we also need to live our lives today. If you’re lucky enough to live by the sea — enjoy it.

• Next weekend in Hobart is the big one for green living: The Sustainable Living Expo 2009, a free event at Princes Wharf, Hobart, from 10 am to 5 pm on Saturday and Sunday. Everything you ever wanted to know about making your home and community more resilient.

Dealing with sea change

The House of Representatives Committee on Climate Change came up with 47 recommendations, including:

• Ensure that Australia contributes the best it can to global emissions reduction.

• Identify places at high risk from wave erosion and determine how waves interact with different landforms.

• Ascertain local government needs in dealing with climate change impacts.

• Establish a National Coastal Zone Database to inform people about how to adapt to changes in their own area.

• Act urgently to protect Australians from threats of dengue fever and chikungunya virus.

• Establish a fund to lessen the impact of natural disasters.

• Assess the vulnerability of coastal infrastructure to inundation from sea level rise and extreme events and take measures to improve the resilience of coastal communities to natural disasters.

• Have the Productivity Commission examine insurance implications of climate change, and revise the Australian building code to increase resilience to climate change impacts.

• Clarify the legal position on climate impacts of public authorities, private landowners, land developers and others.

• Undertake specific measures to protect natural ecosystems and biodiversity.

• Encourage development of self-supporting “sustainable coastal communities”, and focus on capacity building for coastal local councils.

• Establish a national coastal zone management strategy and a government agency to administer it.

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